<template>
  <div class="app-container">
    <el-input v-model="filterText" placeholder="Filter keyword" style="margin-bottom:30px;"/>
    <el-button type="text" @click="dialogFormVisible = true">添加一级分类</el-button>
    <el-tree
      ref="subjectTree"
      :data="subjectList"
      :props="defaultProps"
      :filter-node-method="filterNode"
      :expand-on-click-node="false"
      class="filter-tree"
      default-expand-all
      node-key="id"
    >
      <span slot-scope="{ node, data }" class="custom-tree-node">
        <span>{{ node.label }}</span>
        <span>
          <!-- 使用Chrome的Vue插件调试 -->
          <el-button
            v-if="node.level == 1"
            type="text"
            size="mini"
            @click="() => {dialogFormVisible = true; subject.parentId = data.id}"
          >添加</el-button>
          <el-button
            v-if="node.level == 2 || node.level == 1"
            type="text"
            size="mini"
            @click="() => remove(node, data)"
          >删除</el-button>
        </span>
      </span>
    </el-tree>
    <!-- 添加一级分类dialog -->
    <el-dialog :visible.sync="dialogFormVisible" title="添加分类">
      <el-form :model="subject" label-width="120px">
        <el-form-item label="分类标题">
          <el-input v-model="subject.title"/>
        </el-form-item>
      </el-form>
      <div slot="footer" class="dialog-footer">
        <el-button @click="dialogFormVisible = false">取 消</el-button>
        <el-button type="primary" @click="append()">确 定</el-button>
      </div>
    </el-dialog>
  </div>
</template>

<script>
import subject from "@/api/subject";

export default {
  data() {
    return {
      dialogFormVisible: false,
      subject: {
        title: "",
        parentId: ""
      },
      filterText: "",
      subjectList: [],
      defaultProps: {
        children: "children",
        label: "title"
      }
    };
  },
  created() {
    this.getListSubject();
  },
  watch: {
    filterText(val) {
      this.$refs.tree2.filter(val);
    }
  },

  methods: {
    append(data) {
      if (!this.subject.parentId) {
        this.appendLevelOne()
      } else {
        this.appendLevelTwo()
      }
    },
    appendLevelOne() {
      subject
        .addOneLevel(this.subject)
        .then(response => {
          this.$message({
            type: "success",
            message: "保存成功!"
          });
          this.dialogFormVisible = false;
          this.getListSubject();
        })
        .catch(response => {
          this.$message({
            type: "error",
            message: "保存失败"
          });
        });
    },
    appendLevelTwo() {
      subject
        .addTwoLevel(this.subject)
        .then(response => {
          this.$message({
            type: "success",
            message: "保存成功!"
          });
          this.dialogFormVisible = false;
          this.getListSubject();
          this.subject.title = ''//重置类别标题 
          this.subject.parentId = ''//重置表单parentid

        })
        .catch(response => {
          this.$message({
            type: "error",
            message: "保存失败"
          });
        });
    },
    remove(node, data) {
      this.$confirm("此操作将永久删除该记录, 是否继续?", "提示", {
        confirmButtonText: "确定",
        cancelButtonText: "取消",
        type: "warning"
      })
        .then(() => {
          return subject.removeById(data.id);
        })
        .then(() => {
          // this.getListSubject 刷新列表 效率低
          this.$refs.subjectTree.remove(node); //删除节点效率高
          this.$message({
            type: "success",
            message: "删除成功!"
          });
        })
        .catch(response => {
          if (response === "cancel") {
            this.$message({
              type: "info",
              message: "已取消删除"
            });
          } else {
            this.$message({
              type: "error",
              message: "删除失败"
            });
          }
        });
    },
    getListSubject() {
      subject.getSubjectList().then(response => {
        this.subjectList = response.data.items;
      });
    },
    filterNode(value, data) {
      if (!value) return true;
      return data.title.indexOf(value) !== -1;
    }
  }
};
</script>

